Articulated venetian blind tape



March 16, 1954 E. E. WOLFE ET AL 2,672,193

ARTICULATED VENETIAN BLIND TAPE Filed Jan. 2, 1952 IN V EN TORS ErnestZ'IWo lfe/ Patented Mar. 16, 1954 UNITED STATES PATENT OFFICE ARTICULATED VENETIAN BLIND TAPE Ernest E. Wolfe, West Los Angeles, and Anthony G. Schuck, Los Angeles, Calif., assignors t Schuck Manufacturing 00., Inc., Los Angeles,

14 Claims. 1

This invention relates to Venetian blind tape of the type disclosed in the application of Ernest E. Wolfe, Serial No. 73,623, filed January 29, 1949, now Patent No. 2,601,896.

freely under the influence of gravity, to assume positions of slight inclination in opposite directions, with the respective hinges slightly broken in the direction in which they are intended to The general object of this invention is to pro- 5 fold; and (b) effectively resist the tendency of vide improvements in articulated tape of the the hinge loops to open up under normal tension type disclosed in that application, in which hinge applied to them, even in the uppermost hinge pintles are formed as thin, fiat portions of the loops. links themselves, and in which there is considoth objects ll become apparent in t ereble resulting IOOSeHeSS in the hinges. suing specifications and appended drawings in In the fabricating of Venetian blind tape from hich;

a Series ef Stamped Sheet metal links, hingedly Fig. 1 is an inner side view of a portion of a joined by loops integrally formed at one end of V tian blind a ticulated tape;

each link and looped through slots in the adja- Fig. 2 is an edge view thereof, viewed from cent end of an adjoining link, considerable dif- 5 th left sid f Fig, 1;

ficulty has been encountered in the form of sev- Fi 3 is a fragmentary enlarged detailed secr l p fic problems One of these is the probtional view through two adjacent hinges of the lem of providing definitely for the breaking of ladd r;

O Series Of alternate hinges rdly and Fig. 4 is a transverse vertical sectional view t breaking of the intervening Series Of hinges through a portion of a Venetian blind embodying inwardly, as the ladder is collapsed by moving its the invention with the articulated ladder structure lower end upwardly toward its suspended upper shown in edge elevation; and

e d- W e fairly tight hinges are p y this Fig. 5 is a fragmentary outer side view of the may readily be accomplished by the provision of l dd tru t re,

a fing r or fin ers on n nk projecting p Referring now to the drawings in detail, our each hin e into n emen wi n j c n improved ladder structure comprises a pair of link in such a manner as to restrain breaking opposed ti l t tapes 1 9, 1 of the hinge in the wrong direction, but where ing a plurality of tape links A and A hinged toa loose hinge of the type referred to above, is eth r, end to end, the opposed tapes being employed, the problem is more difiicult. joined by a series of cross links B. The tape links One o t e p fi Objects of the present A, A are arranged with the links A constituting vention is to provide a ladder having improved one series of alternate links and the links A conhinge 100115 Cooperating t p fingers t stituting an intervening series of links disposed lized only on alternate tape links, in a construcalt rnat l b twe n th links A, The hinged tion and arrangement which is such as to render connections between t links A and it possible to p y the loose yp hinge Strueprise a series of alternate, outwardly breaking ture, above e e t and to Obtain a more hinges C and a series of intervening, inwardly re pre-hleeking 0f the hinges- The breaking hinges C. Cross links B are linked pedients 0f the p t, for this general D to the respective tapes at the hinges C, whereby D have not proved fully Satisfactory for the hinges C may fold inwardly between the slats of p p Another problem that has b the collapsed blind structure, as indicated in countered is that of having the hinge loops open j 4, p under the tension applied t0 them- This Each tape link A comprises a rectangular body pr l is particularly aggravated i the hinges a of fairly rigid formable sheet material (such o t uppe links of the ladder; Which Support 5 as sheet metal) having at one end thereof a the entire weight of the extended portion of the pair f l terally spaced, sleeve-like hinge loops V e blind therehelOW- It and having at its opposite end a pair of lat- T p t invention r at primarily to t erally spaced ears 14 provided with respective shape or the hinge 901 5, d has as its Objeet aligned slots I3 which define, at the end extremto provide Venetian blind ladder structure of the itie of said ears Ida respective pair of aligned type indicated, having improved hinge loop struchinge pintles l5. Ears l4 project endwise from ture so constructed and related to the links body portion 9 and define between them a cenof the ladder structure and their arrangement tral notch l6. with relation to each other, as to: (a) cause the Each tape link A comprises a rectangular alternating links of the ladder, when hanging body 9' of similar sheet material, having at one end a pair of laterally spaced, sleeve-like hinge loops iii linked through slots 13 and encircling pintles $5 to constitute hinges C; having at the same end a central loop H, centered between and axially aligned with loop It, received in notch I6 of link A, and spaced inwardly from the inner ends of loops Iii to define spaces !2 for receiving parts of the cross links B; and having at its opposite end a pair of aligned transverse slots i3 in said opposite end. Hinge loops is of links A are linked through slots 13 and encircle pintles IE to constitute hinges C.

Hinges C are substantially concealed by lips i? which are formed as integral extensions of those portions of hinge loops it which immediately adjoin body portions 9 of link A. Similarly, each link A has a lip ll constituting an integral continuation of those portions of loops it which immediately adjoin body portion 9 of link A.

Each cross link B includes a central body portion IQ, for supporting a respective blind slat is (Fig. i) a transverse trunnion portion 2d at each end thereof, and a return bent end portion or finger 2i which is disposed in a common plane with the body portion 53. Each trunnion portion 20 extends through a respective central loop H, and end finger 2| cooperates with body portion If; to embrace the ends of central loop I! and prevent any lateral displacement of the cross link B relative to the tape structure As indicated in Fig. l, alternate links B have their body portions l8 thereof disposed on opposite sides of the median plane of the ladder structure. Thus the cross links B may be utilized as guides for confining a conventional blind operating cord 35 (Fig. 4).

End fingers 2i and opposed body portions is of the cross links B, are accommodated in spaces l2 between loops IE3 and H.

The ladder structure as defined above is largely the same as that disclosed in our above mentioned co-pending application. The present invention provides an improved form of hinge loop structure which is illustrated in detail in Fig. 3, and will now be described.

Each of the hinge loops id, id, includes a portion of the length of lip ll (or ii) as an integral part thereof. Each of the lips H, H includes two sections 22, 23 respectively, defining between them a dihedral angle (which may approach 90) and joined by a bend 24. In the outwardly breaking hinge C, in which hinge loops IE face inwardly, lip section 22 extends outwardly at an obtuse angle from the body portion .9 (or 9') to which it is immediately joined by a bend 27. Lip section 23 is inclined inwardly and across the plane of body portion 9, at an acute angle. To the end edge or" section 23, the separated portions of loops it (or IE3) are joined by bends. These separated portions of the loops are or" roughly U or V section, each including at one'side an arcuate arm 25 integrally joined to bond 25, and at its opposite side an arm 28 having a free end which engages section 22 of lip i! (or ii). Arms26, 28 are joined by a bond 29.

The bends 25 function as stirrups in which trunnions iii (or iii) are fulcrumed and positioned for pivotal movement during the initial stage of folding of the ladder. Such positioning confines the downward pull of .trunnions l5, .55 to lines of contact closely adjacent the free edges of lip sections The end arms 28 of the loops are tucked against the inner walls of lip sections 22, in frictional engagement therewith such as to resist, with an adequate safety factor, any tendency of the loops to open up. The lever arm 7 represented by the distance from bends 25 to the area of engagement between arms 28 and lip section 22 being many times greater than the lever arm i represented by the outermost line of engagement between a trunnion 55 (or I5) and the line where the loops adjoin continuous lip section 23, it will be apparent that the downward force exerted by a trunnion against the bend 25 by which it "is supported may be correspondingly many times "as great as the frictional engagement between .arm28 and lip section 22, before any bending couple is imposed upon bends 25.

In fabricating the tape links, the hinge loops are initially formed with a greater spread between arms 26 and 28 than in the final closed form of the loops, so that the arms 28 will be sprung inwardly when they are forced behind the lip sections .22, and will thereafter exert resilient compressive engagement with lip sections 272.

It will be apparent that the continuous bends 2 1 and 21 between lip sections 22 and 23, and between lip section 22 and body portion 9 (or 9), extending continuously throughout the width of the link, may be given adequate strength to resist deformation under the tension applied thereto by the suspension of the links one by the other, and that the bends 25, which collectively have only a fraction of the full width of the link and correspondingly have only a fraction of the strength of bends 24, 21, have the ability to carry the loads imposed upon them, derived from the fact that said loads are applied closely adjacent to continuous edges of adjoininglip sections 23,

plus the locking of theloops in closed form by the frictional engagement of arms 28 against lip sections 22. .In the latter connection it will be noted that any tendency for the bends 25 to open up must necessarily be accompanied by a tendency for arms 28 to slide against the inner surfacesof lip sections 22, these surfaces being disposed substantially upon the circumference of the axis of bends 2-5 about which the loops would tend to pivot in the opening up process.

The links .of each tape are supported in positions slightly inclined with reference to the general vertical plane of the tape, with alternate links inclined in directions opposite the intervening links. The degree of inclination of the links is determined by means for limiting the spreading movement of the links at hinges C. Such means comprises stop fingers 3B constituting integral portions of links A projecting from the ends thereof which have the hinge loops l8, the fingers so being centered between loops i0, and projecting beyond the hinge axis to engage links A. Hinges C become locked against opening to fully spread positions of the adjacent links, as the result or" pressure of link A against finger to in one direction (as indicated "by arrow 31) and pressure of trunnion 1'5 against loop arm 28 in the opposite direction (as indicated by arrow 32) at a point where the camming efiect or trunnion l5 tending to ride'upwardly against the inclined inner face of bend 25 under lateral force 32 is balanced against the tendency to ride downwardly on said inclined surface under the downward pull of the load imposed thereon. In some cases, the upper end of trunnion iii may engage arm .26 .at bend .29 to establish a final limit to the spreading movement. Each finger 3U defines a dihedral angle with respect to the extended plane of adjoining body portion 9. This dihedral angle is such as to cause adjacent links, in their fully aevaioa extended positions of hinging movement about the axis of hinge C, to assume a dihedral angle with respect to each other which determines a definite initial inward breaking of hinges C.

This restriction of spreading movement of the links at hinge C is utilized to correspondingly determin an initial breaking of the intervening hinges C. It will be apparent, upon reflection, that so long as alternate hinges are restricted in their opening movement so as to determine a definite dihedral angle between the links of said alternate hinges, the same dihedral angle must necessarily be present in the intervening hinges when the ladder is freely suspended, even though such intervening hinges do not have any corresponding means for limiting their opening movement. Furthermore, the movement limiting fingers 30 are disposed at the inner sides of the repective tapes and therefore concealed within the ladder structure, so that the outer sides of the respective tapes do not disclose any projecting fingers. This definitely improves the appearance of the ladder structure. Also, it makes it possible to form, in links A, the integral loops 1 I at the respective positions occupied by fingers 30 in links A.

The hinge loops l0, ill have a cross sectional shape which approximates both the cylindrical and the triangular, lying intermediate the two. It may best be described as a heart shape. It is characterized by the curvature of arms 26 and 28 on a longer radius than that of the approximated cylinder of the same diameter, and the curvature of the connecting bends 25 and 29 on a shorter radius than the radiu of such approximated cylinder. The radii of the arms 26, 28 may be such as to locate the centers thereof approximately at the centers of connecting bends 25 and 24, so that in the folding of the hinges, trunnions l5, l5 may consecutively pivot at approximately the centers of bends 25 and 24 with the edges of trunnions l5 opposite the pivoting edges travelling with roughly uniform clearance from the inner walls of arms 28, 26- respectively. For example, the folding of hinge C may be visualized as a series of pivotal movements wherein the trunnions first pivot at their inner edges upon bends 25, with their outer edges travelling along the inner walls of arms 28, and swinging toward lip section 23 until they have contacted the latter, and then pivot at their outer edge in bends 24 while their inner edges swing arcuately along the inner walls of arms 26.

This approximately triangular shape of the loops has several advantages. The bends 25, of

sharper radius than that of the cylinder approximated by the loop structure, more accurately locate the trunnions supported therein, than in a strictly cylindrical hinge loop. Any engagement of bends 29 by the upper edge of trunnioniS will, owing to the angle of engagement, result more in an upward component of force tending to press arm 28 into even more tight frictional engagement with lip section 22, than the lateral pressure tending to open up the loop. The broad curvature of arm 28 provides a greater area of frictional engagement with lip section 22 than would be attained by a surface of the cylinder approximated by the loop. All of these characteristics contribute to the much greater capacity displaced appreciably inwardly from the axes of the hinges C, in the freely suspended ladder structure. Consequently, as the blind is raised by lifting force applied to the bottom slats, successive pairs of links A, A will be folded inwardly by the upward pressure, applied first to the lower links A of such pair and transferred therefrom to the upper links through hinge C, while the next higher hinge C remains substantially immobilized by the weight of the slats applied thereto through its adjoining cross link B. With the two opposed hinges C initially broken inwardly and their axes disposed inwardly of the axes of the hinges C above and below the same, the inward collapsing of the two pairs of links at their connecting hinges C will be assured.

We claim:

1. A ladder structure for supporting a plurality of slats in a Venetian blind, comprising: a

plurality of flat supporting cross links; and a pair of opposed articulated sheet metal tapes each including alternating first and second series links and a plurality of hinges joining said links end to end, with alternating outwardly breaking hinges linked together by said cross links and intervening inwardly breaking hinges adapted to be received between the slats when the blind is collapsed; said links each having at one end a pair of laterally spaced, aligned, integral sleevelike hinge loops and at its other end a pair of aligned transversely extending slots spaced from said other end to define a pair of trunnions received in the respective hinge loops of the adjoining link, the hinge loops of said inwardly breaking hinges facing inwardly and being disposed largely on the inner side of the plane of their respective links and the hinge loops of the outwardly breaking hinges facing outwardly and being disposed largely on the outer side of the plane of their respective links; said hinge loops each including as an integral portion thereof, a lip of v-section channel form, extending contin uously from side to side of the respective link and including a first lip section joined directly to the body of the link through a bend of obtus angle form and a second lip section inclined in the opposite direction and joined to said first lip section by a substantially right angle bend, and said loops including separated portions each of generally U-shape joined to the free edge of said second lip section and having free end arms frictionally engaged against the inner wall of said first lip section, to lock said loops in closed positions in opposition to the tendency of the loops to open up under the pull of said trunnions.

2. A ladder structure as defined in claim 1, wherein each of said separated loop portions has an intermediate arm joined to said free end arm thereof, and a bend of sharper radius than the overall radius of the loop, joining said intermediate arm to the free edge of said second lip section, said last mentioned bend functioning a a stirrup to support the lower edge of the associated trunnion in closely spaced relation to said free edge of said second lip section so as to minimize the bending moment therein under the downward gravity pull of the load carried by said trunnion and thereby minimize the tendency of the loop to open under said pull.

3. A ladder structure as defined in claim 2, wherein said intermediate and free end arms are of outwardly bowed cross sectional shape, each having a radius greater than the said overall radius of the loop, and joined together by a bend of sharper radius than said overall radius, whereby the loop is of substantially heart shape cross section.

4. A ladder struture as defined in claim 3, wherein the centers of curvature of said intermediate and free end arms are disposed approximately at the centers of said right angle bend joining saidlip section and of said trunnion supporting bend, respectively.

5. A ladder structure for supporting a plurality of slats in a Venetian blind, comprising: a plurality of fiat supporting cross links; and a pair of opposed articulated sheet metal tapes each including alternating first and second series links and a plurality of hinges joining said links end to .end, with alternating outwardly breaking hinges linked together by said cross links and intervening inwardly breaking hinges adapted to be received between the slats when the blind is collapsed; said links each having at one end a pair of laterally spaced, aligned, integral sleevelik hinge loops and at its other end a pair of aligned transversely extending slots spaced from said other end to define a pair of trunnions received in the respective hinge loops of the adjoining link, the hinge loops of said inwardly breaking hinges facing inwardly and being disposed largely on the inner side of the plan of their respective links and the hinge loops of the outwardly breaking hinges facing outwardly and being disposed largely on the outer side of the plane of their respective links; said hinge loops each including as an integral portion thereof, a lip of V-section channel form, extending continuously from side to side of the respective link and including a first lip section joined directly to the body of the link through a bend of obtuse angle form and a second lip section inclined in the opposite direction and joined to said first lip section by a substantially right angle bend, and said loops including separated portions each of generally U-shape joined to the free edge of said second lip section, and said hinge loops being of approximately triangular cross sectional shape, with said separated portions thereof having flattened intermediate and free end arms and bends of sharper radius than the overall radius of the loop, joining said arms and joining said intermediate arms to said free edge of said second lip section, respectively, said last mentioned bends functioning as stirrups to support th associated trunnions in close association with said free edge of the second lip section to minimize the bendlng moment therein under the gravity load imposed thereon by said trunnion.

6. A ladder structure for supporting a plurality of slats in a Venetian blind, comprising: a plurality of fiat supporting cross links; and a pair of opposed articulated sheet metal tapes each including alternating first and second series links and a plurality of hinges joining said links end to end, with alternating outwardly breaking hinges linked together by said cross links and intervening inwardly breaking hinges adapted to be received between the slats when the blind is collapsed; said links each having atone end a pair of laterally spaced, aligned, integral sleevelike hinge loops and at its other end a pair of aligned transversely extending slots spaced from said other end to define a pair of 'trunnions received in the respective hing loops of the adjoining link, th hinge loops of said inwardly breaking hinges .facing inwardly and being disposed largely on the inner side of the plane of their respectiv -links and the hinge-loops of the outwardly breaking hinges facing outwardly and being disposed largely on the outer side of the plane of their respective links; said hinge loops each including as an integral portion thereof, a lip of V-section channel form, extending continuously from side to side of the respectiv link and including a first lip section joined directly to the body of the link through a bend of obtuse angle form and a second lip section inclined in the opposite direction and joined to said first lip section by a substantially right angle bend, and said loops including separated portions each of generally U-shape joined to the free edge of said second lip section, and said hinge loops being of approximately triangular cross sectional shape, with said separated portions thereof having fiattened intermediate and free end arms and bends of sharper radius than the overall radius of the loop, joining said arms and joining said intermediate arms to said free edges of said second lip section, respectively, said last mentioned bends functioning as stirrups to support the assooiated 'trunnions in close association with said free edge of the second lip section to minimize with bending moment therein under the gravity load imposed thereon by said trunnion, and said free end arms being frictionally engaged against the inner wall of said first lip section to lock the loop against the tendency to open under said bending moment.

7. A ladder structure for supporting a plurality of slats in a Venetian blind, comprising: a plurality of supporting cross links; and a pair of opposed articulated sheet metal tapes each including alternating first and second series links and a plurality of hinges joining said links end to end, with alternating outwardly breaking hinges linked together by said cross links and intervening inwardly breaking hinges adapted to be received between the slats when the blind is collapsed; said links each having at one end a pair of laterally spaced, aligned, integral sleevelike hinge loops and at its other end a pair of aligned transversely extending slots spaced from said other end to define a pair of trunnions received in the respective hing loops of the adjoining 'link, said hinge loops each including as an integral portion thereof, a lip of V-section channel form, extending continuously from side to side of the respective link and including a first lip section joined directly to the body of the link through a bend of obtuse angle form and a second lip section inclined in the opposite direction and joined to said first lip section by a substantially right angle bend, and said loops including separated portions each of generally U-shape joined to the free edge of said second lip section and having free end arms frictionally engaged against the inner wall of said first lip section, to lock said loops in closed positions in opposition to the tendency of the loops to open up under the pull of said trunnions.

'8. A ladder structure for supporting a plurality of slats in a Venetian blind, comprising: a plurality of supporting cross links; and a pair of opposed articulated sheet metal tapes each including alternating first and second series links and a plurality of hinges joining said links end to end, said links each having at one end a pair of laterally spaced, aligned, integral sleeve like hinge loops and at its other end a pair of aligned transversely extending slots spaced from said other end to define a pair of trunnions received in the respective hinge loops of the adjoining link, said hinge loops each including as an integral portion thereof, a lip of V-section channel form, extending continuously from side to side of the respective link and including a first lip section joined directly to the body of the link through a bend of obtuse angle form and a second lip section inclined in the opposite direction and joined to said first lip section by a substantially right angle bend, and said loops including separated portions each of generally U-shape joined to the free edge of said second lip section and having free end arms frictionally engaged against the inner wall of said first lip section, to lock said loops in closed positions in opposition to the tendency of the loops to open up under the pull of said trunnions.

9. A ladder structure for supporting a plurality of slats in a Venetian blind, comprising: a plurality of supporting cross links; and a pair of opposed articulated sheet metal tapes each including alternating first and second series links and a plurality of hinges joining said links end to end, with alternating outwardly breaking hinges linked together by said cross links and intervening inwardly breaking hinges adaptedto be received between the slats when the blind is collapsed; said links each having at one end a pair of laterally spaced, aligned, integral sleevelike hinge loops and at its other end a pair of aligned transversely extending slots spaced from said other end to define a pair of trunnions received in the respective hinge loops of the adjoining link, said hinge loops each including as an integral portion thereof, a lip of V-section channel form, including a first lip section joined directly to the body of the link through a bend, and a second lip section inclined in the opposite direction and joined to said first lip section by a bend, and said loops including separated portions each of generally U-shape joined to the free edge of said second lip section and having free end arms frictionally engaged against the inner wall of said first lip section, to lock said loops in closed positions in opposition to the tendency of the loops to open up under the pull of said trunnions.

10. A ladder structure for supporting a plurality of slats in a Venetian blind, comprising: a plurality of supporting cross links; and a pair of opposed articulated sheet metal tapes each including alternating first and second series links and a plurality of hinges joining said links end to end, said links each having at one end a pair of laterally spaced, aligned, integral sleeve-like hinge loops and at its other end a pair of aligned transversely extending slots spaced from said other end to define a pair of trunnions received in the respective hinge loops of the adjoining link, said hinge loops each including as an integral portion thereof, a lip of V-section channel form, including a first lip section joined directly to the body of the link through a bend and a second lip section inclined in the opposite direction and joined to said first lip section by a bend, and said loops including separated portions each of generally U-shape joined to the free edge of said second lip section and having free end arms frictionally engaged against the inner wall of said first lip section, to lock said loops in closed positions in opposition to the tendency of the loops to open up under the pull of said trunnions.

11. A ladder structure as defined in claim 10, wherein each of said separated loop portions has an intermediate arm joined to said free end arm thereof, and a bend of sharper radius than the overall radius of the loop, joining said intermediate arm to the free edge of said second lip section, said last mentioned bend functioning as a stirrup to support the lower edge of the associated trunnion in closely spaced relation to said free edge of said second lip section so as to minimize the bending moment therein under the downward gravity pull of the load carried by said trunnion and thereby minimize the tendency of the loop to open under said pull.

12. A ladder structure as defined in claim 11, wherein said intermediate and free end arms are of outwardly bowed cross sectional shape, each having a radius greater than the said overall radius of the loop, and joined together by a bend of sharper radius than said overall radius, whereby the loop is of substantially heart shape cross section.

13. A ladder structure as defined in claim 12, wherein the centers of curvature of said intermediate and free end arms are disposed approximately at the centers of said right angle bend joining said lip section and of said trunnion supporting bend, respectively.

14. A ladder structure as defined in claim 10, wherein the links of one series have integral stop fingers on the ends thereof which have said hinge loops, said fingers projecting beyond the hinge axis to engage the adjacent link of said other series.

ERNEST E. WOLFE. ANTHONY G. SCHUCK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,037,703 Cameron Apr. 21, 1936 2,061,548 Cameron Nov. 24, 1936 

